JP2002068914A - Method for enhancing antimicrobial activity of inorganic antimicrobial agent carrying silver component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for enhancing antimicrobial activities of an inorganic antimicrobial agent carrying a silver component by which not only the antimicrobial activities of the inorganic antimicrobial agent carrying the silver component can be enhanced, but also the antimicrobial activities of the inorganic antimicrobial agent carrying the silver component having the antimicrobial activities lowered from the initial antimicrobial activities can be recovered to the original activities. SOLUTION: This method for enhancing the antimicrobial activities of the inorganic antimicrobial agent comprises treating the inorganic antimicrobial agent carrying the silver component with an acid solution containing at least one kind selected from the group consisting of nitric acid, sulfuric acid, acetic acid, vinegar, nitric acid-acidified silver nitrate, phosphoric acid, citric acid, malic acid and oxalic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an antibacterial activity of an inorganic antibacterial agent carrying a silver component and an antibacterial activity of an inorganic antibacterial agent carrying a silver component having a lower antibacterial activity from the beginning. The present invention relates to a method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a recoverable silver component.

[0002]

2. Description of the Related Art It has long been known that specific metals such as silver, copper and zinc have an antibacterial effect. In particular, an inorganic antibacterial agent carrying a silver component has been widely put to practical use. As such an inorganic antibacterial agent carrying a silver component, usually, an inorganic compound substrate carried by ion exchange of silver ions, a substance carried as silver oxide or metallic silver, or a silver complex is carried. And those supported as glass components are known.

In general, the antibacterial action of these inorganic antibacterial agents is such that zeolite carrying silver ions exhibits antibacterial properties by releasing silver ions, and zirconium phosphate carrying silver does not release silver ions. Is known to exhibit antibacterial properties by action with light.

[0004]

Among these, the antibacterial action of an inorganic antibacterial agent that releases silver ions is based on the fact that silver ions eluted into an aqueous system react with SH groups of bacterial proteins to denature proteins. At the same time, it is considered that this is due to the reactivity of the hydroxyl radicals generated by the action of silver ions on dissolved oxygen in water.

[0005] However, after the antibacterial agent itself is prepared or manufactured using such an antibacterial agent, the time elapses on the order of months or years, or the environment in a stored state such as heating, pressure, oxygen partial pressure, and sunlight irradiation during that time. Due to the change, silver contained in the inorganic antibacterial agent is clustered (aggregated), and as a result, the amount of silver ion eluted is reduced even if silver is present in the antibacterial agent,
The accompanying decrease in the amount of hydroxyl radical expression inevitably reduces the antibacterial activity.

Accordingly, the present invention enhances the antibacterial activity of an inorganic antibacterial agent carrying a silver component and restores the antibacterial activity of an inorganic antibacterial agent carrying a silver component, which has a lower antibacterial activity from the beginning, to the beginning. It is an object of the present invention to provide a method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component which can be used.

[0007]

SUMMARY OF THE INVENTION According to the present invention, an antibacterial activity can be easily enhanced by treating an inorganic antibacterial agent carrying a silver component with an acid solution. The antibacterial agent has been completed based on the finding that the antibacterial activity can be restored to the initial state.

That is, the present invention provides a method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component, which comprises treating the inorganic antibacterial agent carrying a silver component with an acid solution. .

In the method for enhancing antibacterial activity, the inorganic antibacterial agent may be an inorganic antibacterial agent having reduced antibacterial activity. The inorganic antibacterial agent carrying a silver component preferably releases silver ions, and is particularly preferably a zeolite carrying silver ions. Also,
The inorganic antibacterial agent carrying a silver component is preferably one in which zeolite carrying silver ions is held on a carrier.

The above-mentioned treatment with an acid solution is preferably carried out by immersing an inorganic antibacterial agent carrying a silver component in the acid solution. The immersion in the acid solution is preferably performed at a pH of 2 to 5, and the acid solution is selected from the group consisting of nitric acid, sulfuric acid, acetic acid, vinegar, silver nitrate, nitric acid, phosphoric acid, citric acid, malic acid, and oxalic acid. Preferably, it contains at least one of the above.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The present invention is characterized in that an antibacterial agent carrying a silver component is treated with an acid solution to enhance antibacterial activity.

In the present invention, the inorganic antibacterial agent carrying a silver component means a silver ion, metallic silver, silver oxide, a silver complex or an inorganic compound having silver as a glass component and having antibacterial properties. .

The inorganic antibacterial agent carrying a silver component is not particularly limited as long as it is an inorganic compound carrying a silver component. Examples of the inorganic compound carrying a silver component include activated carbon,
Activated alumina, silica gel, zeolite, hydroxyapatite, zirconium phosphate, titanium phosphate, potassium titanate, hydrated bismuth, hydrated zirconium, hydrotalcites, zinc oxide, silicate glass,
Aluminum magnesium silicate, calcium silicate,
Examples thereof include calcium carbonate and titanium oxide.

The method of supporting the silver component on these inorganic compounds is not particularly limited. For example, a method of supporting the particles by physical adsorption or chemical adsorption, a method of supporting them by ion exchange reaction, a method of supporting them by a binder, and a method of supporting a silver compound. Examples of the method include a method in which the inorganic compound is loaded by being driven into the inorganic compound, a method in which a thin layer of a silver compound is formed on the surface of the inorganic compound by a thin film forming method such as vapor deposition, dissolution deposition reaction, or sputtering.

The amount of the silver component carried by the inorganic antibacterial agent is not particularly limited, but silver is usually 3 to 15 wt%, preferably 8 to 12 wt%.

The method for enhancing the antibacterial activity of the present invention can be applied to the above-mentioned inorganic antibacterial agents whose antibacterial activity has not been reduced. Can also be applied. Here, the inorganic antibacterial agent having a reduced antibacterial activity is defined as a cluster of silver contained in the inorganic antibacterial agent due to environmental changes in storage conditions such as the passage of time or heating, pressure, oxygen partial pressure, and sunlight irradiation. (Agglomeration), which means that the amount of silver ion eluted is reduced even if silver is present in the antibacterial agent. There is no particular limitation, but usually 3 to 15 watts as silver.
What is t%, preferably 8 to 12 wt% is preferable.

The above-mentioned inorganic antibacterial agent may be in the form of powder, granules, spheres, pellets, plates or honeycomb molded products, and may be formed using an inorganic binder such as bentonite or an organic resin. It may be something.

The inorganic antibacterial agent carrying a silver component of the present invention may be carried in combination with another antibacterial component. Other antibacterial components include one or two of zinc, copper, and nickel.
Species or more.

In the present invention, the inorganic antibacterial agent carrying a silver component is preferably one capable of releasing silver ions, particularly preferably zeolite carrying silver ions.

The zeolite of the substrate may be any of natural or synthetic zeolites. Examples of natural zeolites include Analcime (Salcime; S).
iO ₂ / Al ₂ O ₃ = 3.6 to 5.6), Chabazite; SiO ₂ / Al ₂ O ₃ = 3.2
6.0), Clinoptilite
lite; SiO ₂ / Al ₂ O ₃ = 8.5-10.
5), Erionite (SiO ₂ / A)
l ₂ O ₃ = 5.8-7.4), faujasite (Fau)
_{jasite; SiO 2 / Al 2 O} 3 = 4.2~4.
6), mordenite (SiO ₂₎
/ Al ₂ O ₃ = 0.34 to 10.0), Phillipsite (SiO ₂ / Al ₂ O ₃ =
2.6 to 4.4).

The synthetic zeolite is an A-type zeolite (Si
O ₂ / Al ₂ O ₃ = 1.4 to 2.4), X-type zeolite (SiO ₂ / Al ₂ O ₃ = 2 to 3), Y-type zeolite (SiO ₂ / Al ₂ O ₃ = 3 to 6) , Mordenite (S
iO ₂ / Al ₂ O ₃ = 9 to 10).

As a method for supporting the silver ions on the zeolite substrate, widely known methods can be used.
By bringing an aqueous solution of a water-soluble salt of silver into contact with the above-mentioned zeolite, it is possible to easily carry out ion exchange and carry the zeolite on the zeolite.

Further, as the inorganic antibacterial agent carrying a silver component, a zeolite carrying silver ions held on a carrier can be used. As the carrier, resin pellets, biodegradable resin pellets and the like are used. The zeolite supporting silver ions is preferably held on at least the surface of the carrier.

The method for enhancing the antibacterial activity of the inorganic antibacterial agent carrying a silver component according to the present invention comprises treating the inorganic antibacterial agent with an acid solution. As a treatment method using an acid solution,
Any method may be used as long as it is a method of treating the inorganic antibacterial agent by contacting it with an acid solution.For example, a method of immersing the inorganic antibacterial agent in the acid solution, passing the acid solution through the layer of the inorganic antibacterial agent And a method of spraying an acid solution onto the inorganic antibacterial agent.

In the present invention, the enhancement of antibacterial activity can be confirmed by an increase in the amount of hydroxyl radicals expressed. The amount of hydroxyl radical expression depends on the concentration of silver ions eluted from the inorganic antibacterial agent having enhanced antibacterial activity. In other words, after the antibacterial agent itself is prepared or after using such an antibacterial agent, the time elapse of the order of months or months, or during that time, heating, pressure, oxygen partial pressure, environmental changes in the storage state such as sunlight irradiation, The silver contained in the inorganic antibacterial agent is clustered, the amount of silver ions eluted even when the inorganic antibacterial agent is immersed in water decreases, and the amount of generated hydroxyl radicals decreases. When protons are applied by treating with, the number of silver ions increases because the clustered silver ions become single silver ions, silver ions are easily eluted into the aqueous solution, and the expression amount of hydroxyl radicals is improved It is thought to be.

The relationship between the amount of hydroxy radicals expressed and the concentration of silver ions eluted from the inorganic antibacterial agent having enhanced antibacterial activity is shown below.

[0027]

(Equation 1) However, the unit is μM (micromolar), and the proportional constant is a constant that changes depending on the medium conditions.

In the present invention, it is preferable that the hydroxy radical is continuously expressed, and it is preferable to treat the hydroxy radical so that the expressed amount is usually 0.01 μM or more, preferably 0.1 μM or more.

In the present invention, the acid solution is a solution in which an acidic compound that releases protons of an inorganic acid or an organic acid is dissolved in a solvent such as water, acetone, methanol or ethanol, preferably water.

Examples of the inorganic acid include sulfuric acid, sulfurous acid,
Amidosulfuric acid, methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, perchloric acid, periodic acid,
Orthoperiodic acid, permanganic acid, nitric acid, nitrous acid, phosphoric acid,
Phosphorous acid, hypophosphorous acid, arsenic acid, arsenous acid, boric acid, borofluoric acid, hexafluorophosphoric acid, antimony hexafluoride, hexafluoroarsenic acid, chromic acid, hydrochloric acid, chlorite, hypochlorous acid, selenium Examples include acid, selenous acid, cyanic acid, thiocyanic acid, telluric acid, telluric acid, silicic acid, hydrofluoric acid, hexafluorosilicic acid, polyphosphoric acid, metaphosphoric acid, molybdic acid and the like.

Examples of the organic acids include vinegar, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, and myristic acid. , Pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, arachidic acid, isobutyric acid, pivalic acid, isovaleric acid, isocaproic acid, 2-ethylbutyric acid,
3,3-dimethylbutyric acid, isocaprylic acid, 2-ethylhexanoic acid, isocapric acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenic acid , Decenoic acid, undecenoic acid, dodecenoic acid, oleic acid, linoleic acid, linoleic acid, elaidic acid, 2-methylcrotonic acid, 3-methylcrotonic acid, tiglic acid,
Aliphatic monocarboxylic acids such as cinnamonic acid, cyclopropanecarboxylic acid, cyclobutanecarboxylic acid, cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, trichloroacetic acid, tribromoacetic acid, trifluoroacetic acid, phenylacetic acid, glycolic acid, and lactic acid, oxalic acid, and malon Acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecandioic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, monomethyl maleate, malic acid, glutamic acid, tartaric acid, Aliphatic polycarboxylic acids such as citric acid, benzoic acid, toluic acid, ethylbenzoic acid, propylbenzoic acid, butylbenzoic acid, hydroxybenzoic acid, anisic acid, ethoxybenzoic acid, propoxybenzoic acid, butoxybenzoic acid, aminobenzoic acid Acid, N, N-dimethyl Aromatic monocarboxylic acids such as aminobenzoic acid, nitrobenzoic acid, fluorobenzoic acid, resorcinic acid, and cinnamic acid, and aromatic polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, and pyromellitic acid Carboxylic acid, phenol, o-
Phenyl phenol, p-aminophenol, p-nitrophenol, catechol, resorcinol, β-naphthol, 2-chlorophenol, and other phenols.

Of the above-mentioned inorganic and organic acids, nitric acid, sulfuric acid, acetic acid, vinegar, silver nitrate, phosphoric acid, citric acid, malic acid and oxalic acid are preferred, and acetic acid is particularly preferred. Further, the above-mentioned inorganic acid and organic acid are
Species or two or more can be used.

The treatment pH is usually 2 to 5, preferably 3 to 5.
4. The reason for this is that, outside the above-mentioned pH range, the amount of generated hydroxyl radicals is not increased, so the amount is small, and the amount of silver ions eluted is reduced. As a result,
It is not preferable because the antibacterial activity is low and an enhancement method cannot be obtained.

When the treatment time is usually less than 60 minutes, the amount of generated hydroxyl radicals tends to increase as the contact or immersion time increases. From doing
The treatment is preferably performed for 60 minutes or more.

The processing temperature is not particularly limited and is usually 5 to 5
0 ° C., preferably 15-30 ° C.

After treating the inorganic antibacterial agent with the acid solution as described above, the acid solution is removed by washing with a solvent using the inorganic antibacterial agent. If the acid solution remains, it is not preferable because the effect of the acid is added to the surroundings or to the substrate when the antibacterial agent is used.

By doing so, the antibacterial activity of the inorganic antibacterial agent carrying a silver component can be enhanced. In this way, the inorganic antibacterial agents having enhanced antibacterial activity include, for example, melamine resins and silicone resins. , ABS resin, alkyd resin, polyester, polystyrene resin, polypropylene resin, polyethylene resin, nylon, etc., can be made into an antibacterial resin having excellent antibacterial activity, and by processing these resins ,
For example, it can be used as an antibacterial paint, antibacterial film, antibacterial filament, antibacterial toiletry product, antibacterial cutting board, antibacterial kitchenware, antibacterial stationery, antibacterial telephone and the like. Further, if it is contained in a chemically synthesized fiber such as polyester, rayon, acrylic, nylon, cupra, polynosic, etc., it can be used as an antibacterial deodorant fiber. In addition, it can be used as antibacterial sand, water treatment agent, and antibacterial paper.

[0038]

The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

<Relationship between amount of expressed hydroxyl radical and silver ion concentration> A-type zeolite (average particle size of 2.8 to 3.2 μm) supporting 3 wt% of silver ions in 200 mL of liquid is added and eluted from A-type zeolite. The silver ion concentration and the hydroxyl radical concentration were measured. The result is shown in FIG.

The hydroxy radical expression concentration was measured as described below, and the pH was adjusted with carbon dioxide. 180 μL of the above supernatant was accurately collected, and 20 μL of 5,5-dimethyl-1-pyrroline-N-oxide (manufactured by Laboratories) was added thereto. After stirring, 130 μL was placed in a flat cell, and subjected to electron spin resonance ( (ESR) was set on an apparatus (manufactured by JEOL; JES-TE100), and the amount of hydroxy radical was measured (5,5-dimethyl-).
It took 90 seconds from the addition of 1-pyrroline-N-oxide to the measurement. ). In addition, the measurement of the vector was performed using H-tempor.

<Relationship between the amount of silver ion eluted in the solution and the number of viable E. coli cells> Initial concentration of E. coli 5.9 × 10 ⁵ cells / ml 2
3 mg of A-type zeolite (average particle size: 2.8 to 3.2 μm) carrying 3 wt% of silver ions in 00 mL was added, and the relationship between the viable cell count of Escherichia coli and the concentration of silver ions eluted from the A-type zeolite was determined. The result is shown in FIG.

<Relationship between hydroxy radical expression level and viable cell count> Escherichia coli initial concentration 5.9 × 10 ⁵ cells / ml 200
To mL, 3 mg of A-type zeolite (average particle size of 2.8 to 3.2 μm) carrying 3 wt% of silver ions was added, and the relationship between the viable cell count of Escherichia coli and the amount of expressed hydroxy radical was determined.
The result is shown in FIG.

From FIGS. 1 to 3, it can be seen that the concentration of silver ions eluted from A-type zeolite increases and the antibacterial activity increases as the amount of expressed hydroxy radical increases. Therefore, in the present invention, the evaluation was performed using the hydroxyl radical expression concentration as an index of the antibacterial activity.

<Preparation of Inorganic Antibacterial Agent Sample> A large number of base materials (polyethylene pellets, average diameter 3 mm) are charged into a mixer, and the mixer is rotated at high speed. As a result, the base materials come into contact with each other, and the surfaces thereof generate heat and melt. When the surface of the base material is melted, an organic solvent as a melting accelerator,
For example, toluene is charged into the mixer. Thereafter, the A-type zeolite supporting 10.5 wt% of silver ions by ion exchange is put into the mixer, and the mixer is again rotated at a high speed. As a result, the surface of each base material is melted, and the inorganic compound powder supporting silver ions collides with the base material at a high speed, so that the inorganic compound powder supporting silver ions on the surface of the base material is substantially uniform. An adhered inorganic antibacterial agent was obtained.

According to the method described above, as a sample of an inorganic antibacterial agent containing silver, A-type zeolite carrying 10.5 wt% of silver ions by ion exchange (average particle diameter:
2.8-3.2 μm) 3 g to polyethylene pellet 10
The following two types of samples fused to a surface of 0 g were prepared.
The following samples A and B were indistinguishable in appearance.

Sample A: an old zeolite pellet prepared in August 1995 and having reduced antibacterial activity; Sample B; manufactured in the same manner as Sample A, November 1999
New zeolite pellets made in May with no reduced antibacterial activity

<Activation Treatment with Vinegar> Example 1 A sample of 108 inorganic antibacterial agents A and B prepared as described above (average weight of one particle: 0.024526 g) was each 50 ml of a vinegar aqueous solution (pH: 2.67). ) For a predetermined time. Next, an inorganic antibacterial agent sample was collected from the acid aqueous solution, quickly washed with ultrapure water, placed on a filter paper, and the aqueous solution was wiped off to obtain a test sample.

Measurement of Expression Concentration of Hydroxy Radical Next, two of the acid-treated pellets were mixed with 5 mL of ultrapure water.
And stirred for 10 minutes.
L (liter) is accurately collected, and 20 μL of 5,5
-Dimethyl-1-pyrroline-N-oxide (manufactured by Labotech) was added, and after stirring, 130 μL was placed in a flat cell, which was subjected to an electron spin resonance (ESR) apparatus (manufactured by JEOL; J
(ES-TE100) and the amount of hydroxy radical was measured (5,5-dimethyl-1-pyrroline-N-).
It took 90 seconds from the addition of the oxide to the measurement. ). In addition, the measurement of the spectrum was performed using H-tempor.

FIG. 4 shows the change in the expression concentration of hydroxy radical with the treatment time of an old zeolite sample in which the antibacterial activity of A was reduced as the inorganic antibacterial agent sample.
FIG. 5 shows the change in the expression concentration of the hydroxyl radical depending on the treatment time of the zeolite sample in which the antibacterial activity was not reduced.

COMPARATIVE EXAMPLE 1 Except for treating with an aqueous silver nitrate solution instead of vinegar,
The treatment concentration in the same manner as in Example 1 was measured for the expression concentration of hydroxy radical.

FIG. 4 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample in which the antibacterial activity of A was reduced as the inorganic antibacterial agent sample.
FIG. 5 shows the change in the expression concentration of the hydroxyl radical depending on the treatment time of the zeolite sample in which the antibacterial activity was not reduced. From FIGS. 4 and 5, it can be seen that reactivation of silver ions in the zeolite does not require additional silver ions, only hydrogen ions (protons).

From the above, the silver ions existing by ion exchange in the initial stage lose their protons in the zeolite with the passage of time and cluster, and the amount of silver ions eluted even when immersed in water decreases. . As a result, it is considered that the amount of generated hydroxyl radicals was reduced. Then, when protons are given by vinegar, the clustered silver ions become single silver ions, so the number of silver ions in the zeolite increases, and as a result, the silver ions are easily eluted into the aqueous solution, and the hydroxyl radical It is presumed that the expression of is improved.

Example 2 The inorganic antibacterial agent sample B108 prepared above was treated at pH 2.
50 ml of vinegar aqueous solution prepared to 67, 3.5 and 4.5
Except that it was immersed for a predetermined time in the same manner as in Example 1.
The hydroxy radical expression concentration of the antibacterial zeolite pellet after the treatment was measured, and the results are shown in FIG.

From the results shown in FIG. 6, it can be seen that when the treatment pH is 2.67 or 3.5, the hydroxyl radical expression concentration is higher than that when the treatment is performed at pH 4.5.

<Activation Treatment with Acetic Acid> Example 3 The inorganic antibacterial agent samples A and B 108 prepared as described above were prepared using acetic acid, which was inexpensive and easily available from vinegar, using aqueous acetic acid
Example 1 except that H was set to 2.5, 3.5 and 4.5
The hydroxyl radical expression concentration was measured by the same operation as described above.

As an inorganic antibacterial agent sample, an old zeolite sample having a reduced antibacterial activity of A was used, and the change in the expression concentration with the treatment time was shown in FIG. FIG. 8 shows the change in the expression concentration of the hydroxyl radical depending on the treatment time.

FIG. 9 shows the concentration of hydroxyl radical expression due to the pH change of each sample after reaching the equilibrium concentration after 75 minutes of treatment. 7 to 9, the hydroxyl radical expression concentration depends on the treatment pH, and
Is 3.5, the highest hydroxyl radical expression concentration is shown.

<Activation Treatment with Nitric Acid> Example 4 Except that a nitric acid solution was used as the acid solution, Example 3 was carried out except that the pH of the nitric acid was adjusted to 2.5, 3.5 and 4.5.
The amount of hydroxy radical expression was measured in the same manner as described above.

FIG. 10 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample having reduced antibacterial activity of A as an inorganic antibacterial agent sample.
FIG. 11 shows the change in the expression concentration of the hydroxyl radical with the treatment time of the zeolite sample in which the antibacterial activity of B was not reduced. FIG. 12 shows the hydroxyl radical expression concentration due to the pH change of each sample after reaching the equilibrium concentration after 75 minutes of treatment.

From the results shown in FIGS. 10 to 12, it can be seen that the amount of hydroxy radical expression depends on the treatment pH, and that the treatment pH of 3.5 shows the highest amount of hydroxy radical expression.

<Activation with nitric acid-acidic silver nitrate> Example 5 A nitric acid-acidic silver nitrate solution was used as the acid solution, and the pH was set to 2.
The amount of hydroxyl radical expression was measured in the same manner as in Example 3 except that the amounts were adjusted to 5, 3.5, and 4.5.

FIG. 13 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample in which the antibacterial activity of A was reduced as an inorganic antibacterial agent sample.
FIG. 14 shows the change in the expression concentration of the hydroxyl radical with the treatment time for the zeolite sample in which the antibacterial activity of B was not reduced. FIG. 15 shows the hydroxyl radical expression concentration due to the pH change of each sample after reaching the equilibrium concentration after 75 minutes of treatment.

From the results shown in FIGS. 13 to 15, it can be seen that the amount of hydroxy radical expression depends on the treatment pH, and that the treatment pH of 3.5 shows the highest amount of hydroxy radical expression.

<Activation Treatment with Sulfuric Acid> Example 6 A hydroxyl radical was prepared in the same manner as in Example 3 except that a sulfuric acid solution was used as an acid solution and the pH was adjusted to 2.5, 3.5 and 4.5. The expression concentration was measured.

FIG. 16 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample in which the antibacterial activity of A was reduced as the inorganic antibacterial agent sample.
FIG. 17 shows the change in the concentration of generated hydroxyl radicals depending on the treatment time of the zeolite sample in which the antibacterial activity of B was not reduced. In addition, FIG. 18 shows the hydroxyl radical expression concentration due to the pH change of each sample after reaching the equilibrium concentration after the treatment for 75 minutes.

From the results shown in FIGS. 16 to 18, it can be seen that the amount of hydroxy radical expression depends on the treatment pH, and that the treatment pH of 3.5 shows the highest amount of hydroxy radical expression.

<Activation Treatment with Phosphoric Acid> Example 7 A phosphoric acid solution was used as the acid solution, and the pH was 2.5, 3.5.
The hydroxyl radical expression concentration was measured in the same manner as in Example 3 except that the concentration was adjusted to 4.5 and 4.5.

FIG. 19 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample having a reduced antibacterial activity of A as an inorganic antibacterial agent sample.
FIG. 20 shows the change in the concentration of hydroxyl radicals generated by the treatment time for the zeolite sample in which the antibacterial activity of B was not reduced. FIG. 21 shows the hydroxyl radical expression concentration due to the pH change of each sample after reaching the equilibrium concentration after 75 minutes of treatment.

From the results shown in FIGS. 19 to 21, it can be seen that the amount of hydroxy radical expression depends on the treatment pH, and that the treatment pH of 3.5 shows the highest amount of hydroxy radical expression.

<Activation Treatment with Citric Acid> Example 8 A citric acid solution was used as the acid solution, and the pH was adjusted to 2.5,3.
The amount of hydroxy radical expression was measured in the same manner as in Example 3, except that the amounts were adjusted to 5 and 4.5.

FIG. 22 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample having reduced antibacterial activity of A as the antibacterial zeolite sample.
FIG. 23 shows the change in the expression concentration of the hydroxyl radical with the treatment time for the zeolite sample in which the antibacterial activity of B was not reduced.

From the results shown in FIGS. 22 to 23, the treatment with citric acid showed a high hydroxy radical expression amount with respect to the old antibacterial zeolite pellet sample A, but the treatment with the new antibacterial zeolite sample B did not. The effect was small. <Activation Treatment with Malic Acid> Example 9 A malic acid solution was used as the acid solution, and the pH was 2.5 and 3.
The amount of hydroxy radical expression was measured in the same manner as in Example 3, except that the amounts were adjusted to 5 and 4.5.

FIG. 24 shows the change in the expression concentration of hydroxyl radical with the treatment time of an old zeolite sample in which the antibacterial activity of A was reduced as an inorganic antibacterial agent sample.
FIG. 25 shows the change in the concentration of generated hydroxyl radicals with the treatment time for the zeolite sample in which the antibacterial activity of B was not reduced.

From the results shown in FIGS. 24 and 25, it can be seen that the amount of hydroxy radical expression depends on the treatment pH, and that the treatment pH of 3.5 shows the highest amount of hydroxy radical expression.

<Activation Treatment with Oxalic Acid> Example 10 The amount of hydroxyl radicals expressed was measured in the same manner as in Example 3, except that an oxalic acid solution was used as the acid solution and the pH was adjusted to 3.5.

As an inorganic antibacterial agent sample, an old zeolite sample in which the antibacterial activity of A was reduced was used, but a change in the expression concentration of hydroxyl radical with the treatment time and a zeolite sample in which the antibacterial activity of B was not decreased were used. FIG. 26 shows the change in the expression concentration of the hydroxyl radical with the treatment time.

<Evaluation based on acidity index (pKa)> The concentration of hydroxy radical expression after reaching equilibrium with pKa using the dissociation constant (Ka) of the inorganic acid and organic acid used as an index, shows that the antibacterial activity of sample A is reduced. Fig. 2 shows the results obtained by treating the old zeolite pellet and the new zeolite pellet having the antibacterial activity of Sample B, respectively.
7, shown in FIG. However, the relationship between the acidity index (pKa) and the dissociation constant (Ka) is

[0078]

(Equation 2) It is.

From the results shown in FIGS. 27 and 28, when the hydroxyl radical expression concentration of the old zeolite pellet before the acid treatment was 0.23 μM and the hydroxyl radical expression concentration of the new zeolite pellet was 0.31 μM, almost pK
It can be seen that the hydroxy radical expression concentration after the acid treatment showed a moderate quadratic increase with the increase in a.

[0080]

As described above, according to the method for enhancing an inorganic antibacterial agent carrying a silver component of the present invention, the antibacterial activity is reduced by treating the inorganic antibacterial agent carrying a silver component with an acid solution. In the case of an inorganic antibacterial agent, it is possible to restore the antibacterial activity to the initial state, and it is possible to enhance the antibacterial activity of new inorganic antibacterial agents whose antibacterial activity is not reduced It works.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a hydroxyl radical concentration and a silver ion concentration in a solution depending on a difference in pH.

FIG. 2 is a view showing the relationship between the number of log surviving Escherichia coli and the silver ion concentration in a solution depending on the pH.

FIG. 3 is a graph showing the relationship between the number of log-live Escherichia coli and the concentration of hydroxy radicals depending on the pH.

FIG. 4 (A) is a diagram showing activation of old zeolite pellets with vinegar and an aqueous solution of silver nitrate.

FIG. 5 (B) shows the activation of new zeolite pellets with vinegar and silver nitrate aqueous solution.

FIG. 6 (B) is a diagram showing the activation (pH change) of vinegar by new zeolite pellets.

FIG. 7A shows activation of old zeolite pellets by acetic acid.

FIG. 8 (B) shows the activation of new zeolite pellets with acetic acid.

FIG. 9 shows the effect of pH on acetic acid activation of (A) old and (B) new zeolite pellets.

FIG. 10 (A) shows activation of old zeolite pellets with nitric acid.

FIG. 11 (B) shows the activation of new zeolite pellets with nitric acid.

FIG. 12 shows the effect of pH on activation of nitric acid in (A) old and (B) new zeolite pellets.

FIG. 13 (A) is a diagram showing activation of an old zeolite pellet by nitric acid-acidic silver nitrate aqueous solubility.

FIG. 14 (B) shows activation of a new zeolite pellet by nitric acid-acidic silver nitrate aqueous solubility.

FIG. 15: pH for activation of (A) old and (B) new zeolite pellets by nitric acid silver nitrate aqueous solubility
FIG.

FIG. 16 (A) shows activation of old zeolite pellets by sulfuric acid.

FIG. 17 (B) shows activation of a new zeolite pellet by sulfuric acid.

FIG. 18 shows the effect of pH on activation of (A) old and (B) new zeolite pellets with sulfuric acid.

FIG. 19 (A) shows activation of old zeolite pellets by phosphoric acid.

FIG. 20 (B) shows activation of a new zeolite pellet by phosphoric acid.

FIG. 21 shows the effect of pH on phosphoric acid activation of (A) old and (B) new zeolite pellets.

FIG. 22 (A) shows activation of old zeolite pellets by citric acid.

FIG. 23 (B) shows activation of new zeolite pellets by citric acid.

FIG. 24 (A) shows activation of old zeolite pellets by malic acid.

FIG. 25 (B) shows activation of new zeolite pellets by malic acid.

FIG. 26 is a diagram showing activation of zeolite pellets by oxalic acid (pH 3.5).

FIG. 27 (A) is a diagram showing the relationship between the acidity index (pKa) of each acid in which old zeolite pellets are immersed and the concentration of hydroxyl radicals.

FIG. 28 (B) is a diagram showing the relationship between the acidity index (pKa) of each acid in which new zeolite pellets are immersed and the concentration of hydroxyl radicals.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kenji Uemoto 3-4-243 Fukumachi, Nishiyodogawa-ku, Osaka-shi, Osaka Inside Nippon Chemical Industry Co., Ltd. Nishiyodogawa Plant (72) Inventor Muneo Mita 9 Kameido, Koto-ku, Tokyo No. 11-1 Nippon Kagaku Kogyo Co., Ltd. Research and Development Division (72) Inventor Daisuke Tobe 11-14 Higashinakacho, Urawa-shi, Saitama F-term (reference) 4H011 AA02 BA01 BB18 BC18 BC19 DA03 DC05

Claims (8)

[Claims] 1. A method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component, comprising treating the inorganic antibacterial agent carrying a silver component with an acid solution. 2. The inorganic antibacterial agent carrying the silver component,
The method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component according to claim 1, wherein the antibacterial activity is reduced. 3. The inorganic antibacterial agent carrying the silver component,
The method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component according to claim 1 or 2, which releases silver ions. 4. The inorganic antibacterial agent carrying the silver component,
The method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component according to any one of claims 1 to 3, wherein the zeolite is a zeolite carrying silver ions. 5. The inorganic antibacterial agent carrying the silver component,
The method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component according to any one of claims 1 to 4, wherein the carrier contains zeolite carrying silver ions. 6. The antibacterial activity of the silver component-carrying inorganic antibacterial agent according to any one of claims 1 to 5, wherein the silver component-carrying inorganic antibacterial agent is immersed in an acid solution for treatment. How to augment. 7. The method for enhancing the antibacterial activity of a silver component-carrying inorganic antibacterial agent according to any one of claims 1 to 6, wherein the acid solution is treated at a pH of 2 to 5. 8. The acid solution according to claim 1, wherein the acid solution contains at least one selected from the group consisting of nitric acid, sulfuric acid, acetic acid, vinegar, silver nitrate, phosphoric acid, citric acid, malic acid and oxalic acid. 7. A method for enhancing the antibacterial activity of an inorganic antibacterial agent carrying a silver component according to any one of items 7 to 7.